Cathode ray tube

Abstract

In a cathode ray tube panel, contour lines of uniform thickness are continuous, closed loops without discontinuities at the periphery of the screen providing a natural picture throughout the panel. Hence, a distorted picture rarely occurs at the periphery of the panel.

What is claimed is: 
     
       1. A cathode ray tube comprising a phosphor screen on the inner surface of a curved rectangular panel whose central axis is perpendicular to the center of said phosphor screen, substantially having a predetermined ratio between the longer and shorter lengths, provided that, when a plane in contact with the center of said panel is defined as a tangent plane, the longer axis of said panel which extends in the horizontal direction of said tangent plane is designated as the X-axis, the shorter axis which extends in the vertical direction is designated as the Y-axis, the axis perpendicular to said tangent plane and passing through the center of said panel is designated as the Z-axis, and an arbitrary point on each of said X-axis and Y-axis are designated as arbitrary points a and b having the same ratio as said predetermined ratio between the longer and shorter lengths of said panel, wherein the thickness of said panel along a line through said arbitrary point a of said X-axis drawn perpendicular to said tangent plane is the same as that of said panel along a line through said arbitrary point b of said Y-axis drawn perpendicular to said tangent plane, and contour lines are positioned within a triangular region formed by a straight line of X coordinates at X=a, a straight line of Y coordinates at Y=b, and a line connecting said points a and b, or are placed on a line obtained by connecting said straight line of X coordinates at X=a and said straight line of Y coordinates at Y=b, or a straight line connecting said points a and b, thereby eliminating discontinuous points of said contour lines throughout a screen.   
     
     
       2. A cathode ray tube as claimed in claim 1, wherein said contour lines of said panel are spaced apart from each other at predetermined intervals. 
     
     
       3. A panel for a cathode ray tube comprising: a panel having a curved rectangular outer surface and a central axis orthogonal to said outer surface, a curved rectangular inner surface, and a thickness between said outer and inner surfaces measured along a direction parallel to the central axis, each of said outer and inner surfaces having a longer side and a shorter side in a predetermined ratio, the longer side being designated as the X-axis and the shorter side being designated as the Y-axis, wherein at each arbitrary point a on the X-axis and each arbitrary point b on the Y-axis chosen in the predetermined ratio the thickness at the arbitrary point a is the same as the thickness at the arbitrary point b and contour lines of uniform thickness connecting points a and b lie within a triangle defined by a line X =a, a line Y =b and a straight line connecting the points a and b.   
     
     
       4. The panel of claim 3 wherein the contour lines of the panel are continuous closed lines lying within the sides of the panel whereby picture distortion of the panel in a cathode ray tube is minimized. 
     
     
       5. The panel of claim 3 wherein the predetermined ratio is 4:3. 
     
     
       6. A cathode ray tube comprising: a curved rectangular panel having an orthogonal central axis, a thickness measured parallel to the central axis, and a longer side and a shorter side in a predetermined ratio, the longer side extending along an X-axis direction and the shorter side extending along a Y-axis direction wherein at an arbitrary point a on the X-axis and an arbitrary point b on the Y-axis having a ratio equal to the predetermined ratio the thickness of panel at the point a is equal to the thickness of the panel at the point b and contour lines of uniform thickness connecting points a and b lie within a triangle defined by a line X =a, a line Y =b and a straight line connecting the points a and b.   
     
     
       7. The cathode ray tube of claim 6 wherein the contour lines of the panel are continuous closed lines lying within the sides of the panel whereby picture distortion in the cathode ray tube is minimized. 
     
     
       8. The cathode ray tube of claim 6 wherein the predetermined ratio of the longer side to the shorter side is 4:3.